2,290 research outputs found
Bioremediation of water recirculation in white shrimp culture using autochthonous microbiota of red mangrove
La actividad acuícola en el cultivo del camarón blanco utilizando agua recirculante deteriora la calidad del agua por la acción hidrodinámica aguametabolitos- materia orgánica, que generan impactos negativos en la producción del crustáceo. El objetivo de esta investigación es demostrar que la microbiota autóctona extraída del mangle rojo estimula la biorremediación. Para este fin se sometió la microbiota a un proceso de bioaumentación que enriquece su biodiversidad, de tal forma que al ser utilizada garantice la actividad biorremediadora. La aplicación del tratamiento se inicia con el diagnóstico de calidad del agua en las diferentes etapas del proceso, a través del monitoreo de compuestos tóxicos como, amonio, nitritos y nitratos y la evaluación de la biodiversidad microbiana utilizando técnicas metagenómicas como la Prueba de Reacción de la Polimerasa, Electroforesis en la comprobación del ADN y su secuenciación mediante la técnica ILLUMINA. Los resultados revelan que los parámetros tóxicos mantienen niveles óptimos de calidad con la aplicación de la microbiota compuesta por 1780 especies microbianas. Estadísticamente se demostró la disminución significativa de niveles de compuestos tóxicos que comprueba la hipótesis, de que la microbiota del mangle rojo actúa eficazmente en la biorremediación del agua en el cultivo de camarón blanco.The aquaculture activity in the white shrimp culture using recirculating water deteriorates the quality of the water by the hydrodynamic action of watermetabolites- organic matter, which generate negative impacts on the production of the crustacean. The objective of this research is to demonstrate that the autochthonous microbiota extracted from the red mangrove stimulates bioremediation. For this purpose, the microbiota was subjected to a process of bioaugmentation that enriches its biodiversity, so that when used, it guarantees bioremediation activity. The application of the treatment begins with the diagnosis of water quality in the different stages of the process, through the monitoring of toxic compounds such as ammonium, nitrites and nitrates and the evaluation of microbial biodiversity using metagenomic techniques such as the Reaction Test of the Polymerase, Electrophoresis in DNA testing and sequencing using the ILLUMINA technique. The results reveal that the toxic parameters maintain optimum levels of quality with the application of the microbiota composed of 1780 microbial species. Statistically it was demonstrated the significant decrease of levels of toxic compounds that the hypothesis proves, that the red mangrove microbiota acts efficiently in the bioremediation of water in the white shrimp culture
Zero Temperature Properties of RNA Secondary Structures
We analyze different microscopic RNA models at zero temperature. We discuss
both the most simple model, that suffers a large degeneracy of the ground
state, and models in which the degeneracy has been remove, in a more or less
severe manner. We calculate low-energy density of states using a coupling
perturbing method, where the ground state of a modified Hamiltonian, that
repels the original ground state, is determined. We evaluate scaling exponents
starting from measurements of overlaps and energy differences. In the case of
models without accidental degeneracy of the ground state we are able to clearly
establish the existence of a glassy phase with .Comment: 20 pages including 9 eps figure
Like-charge attraction through hydrodynamic interaction
We demonstrate that the attractive interaction measured between like-charged
colloidal spheres near a wall can be accounted for by a nonequilibrium
hydrodynamic effect. We present both analytical results and Brownian dynamics
simulations which quantitatively capture the one-wall experiments of Larsen and
Grier (Nature 385, p. 230, 1997).Comment: 10 pages, 4 figure
VAMOS: a Pathfinder for the HAWC Gamma-Ray Observatory
VAMOS was a prototype detector built in 2011 at an altitude of 4100m a.s.l.
in the state of Puebla, Mexico. The aim of VAMOS was to finalize the design,
construction techniques and data acquisition system of the HAWC observatory.
HAWC is an air-shower array currently under construction at the same site of
VAMOS with the purpose to study the TeV sky. The VAMOS setup included six water
Cherenkov detectors and two different data acquisition systems. It was in
operation between October 2011 and May 2012 with an average live time of 30%.
Besides the scientific verification purposes, the eight months of data were
used to obtain the results presented in this paper: the detector response to
the Forbush decrease of March 2012, and the analysis of possible emission, at
energies above 30 GeV, for long gamma-ray bursts GRB111016B and GRB120328B.Comment: Accepted for pubblication in Astroparticle Physics Journal (20 pages,
10 figures). Corresponding authors: A.Marinelli and D.Zaboro
Single-molecule experiments in biological physics: methods and applications
I review single-molecule experiments (SME) in biological physics. Recent
technological developments have provided the tools to design and build
scientific instruments of high enough sensitivity and precision to manipulate
and visualize individual molecules and measure microscopic forces. Using SME it
is possible to: manipulate molecules one at a time and measure distributions
describing molecular properties; characterize the kinetics of biomolecular
reactions and; detect molecular intermediates. SME provide the additional
information about thermodynamics and kinetics of biomolecular processes. This
complements information obtained in traditional bulk assays. In SME it is also
possible to measure small energies and detect large Brownian deviations in
biomolecular reactions, thereby offering new methods and systems to scrutinize
the basic foundations of statistical mechanics. This review is written at a
very introductory level emphasizing the importance of SME to scientists
interested in knowing the common playground of ideas and the interdisciplinary
topics accessible by these techniques. The review discusses SME from an
experimental perspective, first exposing the most common experimental
methodologies and later presenting various molecular systems where such
techniques have been applied. I briefly discuss experimental techniques such as
atomic-force microscopy (AFM), laser optical tweezers (LOT), magnetic tweezers
(MT), biomembrane force probe (BFP) and single-molecule fluorescence (SMF). I
then present several applications of SME to the study of nucleic acids (DNA,
RNA and DNA condensation), proteins (protein-protein interactions, protein
folding and molecular motors). Finally, I discuss applications of SME to the
study of the nonequilibrium thermodynamics of small systems and the
experimental verification of fluctuation theorems. I conclude with a discussion
of open questions and future perspectives.Comment: Latex, 60 pages, 12 figures, Topical Review for J. Phys. C (Cond.
Matt
Relative Efficacy of AS03-Adjuvanted Pandemic Influenza A(H1N1) Vaccine in Children: Results of a Controlled, Randomized Efficacy Trial
Background. the vaccine efficacy (VE) of 1 or 2 doses of AS03-adjuvanted influenza A(H1N1) vaccine relative to that of 2 doses of nonadjuvanted influenza A(H1N1) vaccine in children 6 months to <10 years of age in a multinational study conducted during 2010-2011.Methods. A total of 6145 children were randomly assigned at a ratio of 1: 1: 1 to receive 2 injections 21 days apart of A/California/7/2009(H1N1)-AS03 vaccine at dose 1 and saline placebo at dose 2, 2 doses 21 days apart of A/California/7/2009(H1N1)-AS03 vaccine (the Ad2 group), or 2 doses 21 days apart of nonadjuvanted A/California/7/2009(H1N1) vaccine (the NAd2 group). Active surveillance for influenza-like illnesses continued from days 14 to 385. Nose and throat samples obtained during influenza-like illnesses were tested for A/California/7/2009 (H1N1), using reverse-transcriptase polymerase chain reaction. Immunogenicity, reactogenicity, and safety were assessed.Results. There were 23 cases of confirmed 2009 pandemic influenza A(H1N1) (A[H1N1]pdm09) infection for the primary relative VE analysis. the VE in the Ad2 group relative to that in the NAd2 group was 76.8% (95% confidence interval, 18.5%-93.4%). the benefit of the AS03 adjuvant was demonstrated in terms of the greater immunogenicity observed in the Ad2 group, compared with the NAd2 group.Conclusion. the 4-8-fold antigen-sparing adjuvanted pandemic influenza vaccine demonstrated superior and clinically important prevention of A(H1N1)pdm09 infection, compared with nonadjuvanted vaccine, with no observed increase in medically attended or serious adverse events. These data support the use of adjuvanted influenza vaccines during influenza pandemics.GlaxoSmithKline BiologicalsUniv Melbourne, Murdoch Childrens Res Inst, Carlton, Vic 3010, AustraliaUniv Melbourne, Melbourne Sch Populat & Global Hlth, Carlton, Vic 3010, AustraliaGlaxoSmithKline Vaccines, King of Prussia, PA USANovavax, Rockville, MD USAMary Chiles Gen Hosp, Dept Pediat, Manila, PhilippinesDe La Salle Hlth Sci Inst, Dept Pediat, Dasmarinas City, PhilippinesRes Inst Trop Med, Dept Hlth, Muntinlupa, PhilippinesUniversidade Federal de São Paulo, Dept Pediat, São Paulo, BrazilFac Ciencias Med Santa Casa São Paulo, Dept Pediat, São Paulo, BrazilAssoc Fundo Incent Pesquisa, São Paulo, BrazilInst Costarricense Invest Clin, San Jose, Costa RicaNatl Inst Publ Hlth Mexico, Cuernavaca, Morelos, MexicoUniv Autonoma Nuevo Leon, Serv Med, Monterrey, MexicoInst Nacl Pediat Mexico, Mexico City, DF, MexicoHosp Gen Durango, Durango, MexicoPhramongkutklao Hosp, Infect Dis Unit, Dept Pediat, Bangkok, ThailandKhon Kaen Univ, Dept Pediat, Fac Med, Khon Kaen, ThailandNatl Healthcare Grp Polyclin, Singapore, SingaporeCtr Estudios Infect Pediat, Cali, ColombiaGlaxoSmithKline Vaccines, Wavre, BelgiumGlaxoSmithKline Vaccines, Rixensart, BelgiumUniversidade Federal de São Paulo, Dept Pediat, São Paulo, BrazilWeb of Scienc
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